摘要
Cyclic phosphoester monomer ethyl ethylene phosphate (EEP) modified poly(ethylenimine) (PEI),denoted as PEI-EEP,was developed for gene delivery.Three PEI-EEP polymers were synthesized and their structures were characterized by 1H and 31P NMR methods.All the PEI-EEP polymers could condense DNA efficiently at N/P ratios higher than 0.5/1.The physiochemical characteristics of PEI-EEP/DNA complexes were analyzed by particle size and zeta potential measurements.The particle sizes of complexes were around 160–250 nm,and their zeta potentials were around 30–45 mV at the N/P ratios ranging from 10/1 to 50/1.In vitro cell viability and transfection ability were evaluated in HEK293 and HeLa cells using PEI as the control.The cytotoxicity of PEI-EEP and PEI-EEP/DNA complexes was lower than that of PEI and its complexes with DNA.The transfection efficiency of PEI-EEP/DNA complexes was correlated to modification degrees with phosphoester.When the modification of phosphoester to PEI was moderate,the PEI-EEP1/DNA and PEI-EEP2/DNA complexes exhibited comparable or even higher transfection ability than PEI/DNA complex at its optimal N/P ratio in the absence of serum.However,transfection efficiency of PEI-EEP3 reduced dramatically.More importantly,the PEI-EEP exhibited higher transfection efficiency in the presence of 10% serum than that without serum.Therefore,PEI-EEP polymers may be attractive vectors for non-viral gene therapy.
Cyclic phosphoester monomer ethyl ethylene phosphate （EEP） modified poly（ethylenimine） （PEI）, denoted as PEI-EEP, was developed for gene delivery. Three PEI-EEP polymers were synthesized and their structures were characterized by ^1H and ^31p NMR methods. All the PEI-EEP polymers could condense DNA efficiently at N/P ratios higher than 0.5/1. The physiochemical characteristics of PEI-EEP/DNA complexes were analyzed by particle size and zeta potential measurements. The particle sizes of complexes were around 160-250 nm, and their zeta potentials were around 30-45 mV at the N/P ratios ranging from 10/1 to 50/1. In vitro cell viability and transfection ability were evaluated in HEK293 and HeLa cells using PEI as the control. The cytotoxicity of PEI-EEP and PEI-EEP/DNA complexes was lower than that of PEI and its complexes with DNA. The transfection efficiency of PEI-EEP/DNA complexes was correlated to modification degrees with phosphoester. When the modification of phosphoester to PEI was moderate, the PEI-EEP1/DNA and PEI-EEP2/DNA complexes exhibited comparable or even higher transfection ability than PEI/DNA complex at its optimal N/P ratio in the absence of serum. However, transfection efficiency of PEI-EEP3 reduced dramatically. More importantly, the PEI-EEP exhibited higher transfection efficiency in the presence of 10% serum than that without serum. Therefore, PEI-EEP polymers may be attractive vectors for non-viral gene therapy.
基金
supported by the National Basic Research Program of China (973 Program,2010CB934001)
